Blimp: Add BlobChannel Helium messages and delegate impls.

blimp/net/blob_channel/helium_blob_sender_delegate.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "blimp/net/blob_channel/helium_blob_sender_delegate.h"
+
+#include "blimp/common/create_blimp_message.h"
+#include "blimp/common/proto/blimp_message.pb.h"
+#include "blimp/common/proto/blob_channel.pb.h"
+#include "net/base/net_errors.h"
+
+namespace blimp {
+namespace {
+
+void DoNothingCompletionCallback(int) {}

[Wez, 2016/05/20 21:46:18]

Is there no common no-op callback? e.g. what happens if you just pass
net::CompletionCallback()..?

[Kevin M, 2016/05/23 20:48:08]

Can't find any no-op *completion callbacks*.

Running a net::CompletionCallback() results in a segmentation fault.

[Wez, 2016/05/24 01:18:40]

*sadcodepanda*

+
+}  // namespace
+
+HeliumBlobSenderDelegate::HeliumBlobSenderDelegate() {}
+
+HeliumBlobSenderDelegate::~HeliumBlobSenderDelegate() {}
+
+void HeliumBlobSenderDelegate::DeliverBlob(const BlobId& id, BlobDataPtr data) {
+  DCHECK(outgoing_processor_);

[Wez, 2016/05/20 21:46:18]

nit: You're going to deref that later on, so you don't really need the DCHECK.

[Kevin M, 2016/05/23 20:48:08]

Done.

+
+  std::unique_ptr<BlobChannelMessage> message(new BlobChannelMessage);
+  message->set_type(BlobChannelMessage::TRANSFER_BLOB);
+  message->set_payload(&data->data[0], data->data.size());
+  message->set_blob_id(id);
+  outgoing_processor_->ProcessMessage(CreateBlimpMessage(std::move(message)),
+                                      base::Bind(&DoNothingCompletionCallback));
+}
+
+void HeliumBlobSenderDelegate::ProcessMessage(
+    std::unique_ptr<BlimpMessage> message,
+    const net::CompletionCallback& callback) {
+  NOTIMPLEMENTED();
+  callback.Run(net::OK);

[Wez, 2016/05/20 21:46:18]

Don't return OK if it's not-implemented; if we find code starts calling it then
it'll generate log spam rather than crashing or disconnecting.

[Kevin M, 2016/05/23 20:48:08]

Done.

+}
+
+}  // namespace blimp